A. Ethyl (E)-2-cyano-6-octenoate. A solution of 38.4 g. (0.384 mole) of (E)-4-hexen-1-ol (Note 1) in 160 ml. of anhydrous pyridine is placed in a 1-l. Erlenmeyer flask equipped with a magnetic stirring bar, and the solution is cooled in an ice bath. Over 1 hour, 91.5 g. (0.478 mole) of p-toluenesulfonyl chloride (Note 2) is added portionwise and with stirring to the reaction mixture while maintaining the temperature at 0–5°. The resulting slurry is allowed to stand overnight (Note 3) in a refrigerator, then poured into 500 g. of an ice-water mixture. The reaction mixture is extracted with four 150-ml. portions of diethyl ether, and the combined ethereal extracts are washed successively with four 150-ml. portions of 2 N sulfuric acid, 50 ml. of aqueous saturated sodium hydrogen carbonate, and two 50-ml. portions of water. The ethereal solution is dried over anhydrous sodium sulfate, and the solvent removed on a rotary evaporator at 25°, yielding 76–88 g. (78–91%) of crude (E)-4-hexen-1-yl p-toluenesulfonate as a pale yellow oil (Note 4).

A dry, 2-l., three-necked, round-bottomed flask is equipped with a sealed mechanical stirrer, a thermometer, and a pressure-equalizing dropping funnel fitted with a calcium chloride drying tube. Sodium hydride dispersion (Note 5), [19.2 g. of a 50% w/w suspension in mineral oil, 9.6 g. (0.40 mole) of sodium hydride] is placed in the flask, and 100 ml. of anhydrous pentane is added. After the dispersion has been stirred, the sodium hydride is allowed to settle, and the supernatant liquid is removed with a pipet or a siphon. This washing operation is repeated with two additional 100-ml. portions of pentane, and 400 ml. of anhydrous N,N-dimethylformamide (Note 6) is then added to the reaction flask. To the vigorously stirred suspension of sodium hydride in N,N-dimethylformamide is added, dropwise over 30 minutes, 68 g. (0.60 mole) of ethyl cyanoacetate (Note 7). The mixture is stirred until a clear solution is obtained before all of the previously prepared crude (E)-4-hexen-1-yl p-toluenesulfonate, dissolved in 100 ml. of anhydrous N,N-dimethylformamide (Note 6), is added in one portion. The resulting solution is slowly heated to 100°, with continuous stirring, over a period of 3 hours. During this time the reaction becomes dark red, and crystalline sodium p-toluenesulfonate separates. The mixture is allowed to stand overnight at room temperature, then transferred to a 2-l., one-necked, round-bottomed flask, and most of the solvent is removed on a rotary evaporator. The residual semisolid is mixed with 700 ml. of water and extracted with three 250-ml. portions of ether. The combined ethereal extracts are dried over anhydrous sodium sulfate and concentrated on a rotary evaporator. The residual liquid is fractionally distilled under reduced pressure through a 12-cm. Vigreux column. After removal of a low-boiling forerun, b.p. 54–57° (0.2 mm.), containing mainly ethyl cyanoacetate, 34.5–38.4 g. (46–51%) of colorless ethyl (E)-2-cyano-6-octenoate is collected, b.p. 84–86° (0.2 mm.), n_D25 1.4458 (Note 8) and (Note 9).

B. Ethyl 1-cyano-2-methylcyclohexanecarboxylate. A 2-l., three-necked, round-bottomed flask is equipped with a heating mantle, a Teflon®-coated magnetic stirring bar, a 1-l. pressure-equalizing dropping funnel fitted with a Teflon® stopcock (Note 10), a stopper, and a reflux condenser fitted with a nitrogen-inlet tube. The apparatus is flushed with nitrogen, and 200 ml. of freshly distilled cyclohexane and 0.30 g. (0.0012 mole) of benzoyl peroxide are added to the flask. While a static nitrogen atmosphere is maintained in the flask (Note 11), a solution of 5.00 g. (0.0270 mole) of ethyl (E)-2-cyano-6-octenoate in 800 ml. of freshly distilled cyclohexane is added from the dropping funnel to the stirred, refluxing benzoyl peroxide solution over a period of 40 hours (Note 10). Three additional 0.30-g. (0.0012-mole) portions of benzoyl peroxide (total: 1.2 g., 0.0050 mole, (Note 11)), are added at 12-hour intervals during the addition of the unsaturated ester. After the addition of the unsaturated ester and the benzoyl peroxide is complete, the reaction mixture is refluxed with stirring for an additional 20 hours (Note 12). The resulting colorless to pale-yellow solution is concentrated on a rotary evaporator to approximately 200 ml., diluted with 250 ml. of ether, and washed with 100 ml. of aqueous saturated iron(II) sulfate to destroy any unchanged benzoyl peroxide. The organic layer is then washed successively with two 200-ml. portions of aqueous saturated sodium hydrogen carbonate and two 200-ml. portions of water and dried over anhydrous calcium chloride. The solvent is removed on a rotary evaporator, and the residual liquid is fractionally distilled under reduced pressure through a 5-cm. Vigreux column. After separation of a 0.16–0.25-g. (3–5%) forerun, b.p. 63–64° (0.2 mm.), n_D25 1.4550–1.4560, containing (Note 13) primarily the cyclized product, 3.68–3.82 g. (74–76%) of colorless ethyl 1-cyano-2-methylcyclohexanecarboxylate is collected, b.p. 64–75° (0.2 mm.), n_D25 1.4532–1.4539 (Note 14) and (Note 15).